Evaluation of whole lung 3D dynamic oxygen-enhanced MRI

RATIONALE: Dynamic oxygen-enhanced MRI (dOEMRI) provides imaging biomarkers of regional lung ventilation and perfusion1. Previously, dOEMRI has been limited to single slice imaging. Capturing the whole lung within a single breathing cycle increases the utility of dOEMRI in identifying regional alterations in lung function. In this work, we evaluate a novel quantitative whole lung 3D dOEMRI protocol based on a single-shot 3D MPRAGE sequence available on many scanners2. METHODS: Sequence parameters were optimised to maximise contrast in the lung when switching from air to O2 during free breathing. The protocol was evaluated on a 1.5T Philips Achieva scanner in 4 healthy volunteers (3 which had repeat scans). Baseline T1 maps were acquired while subjects breathed medical air. This was followed by a 15min dynamic scan (temporal resolution 10s), during which gas supply was switched from air to 100% O2, and back to air. Dynamic data were converted to ΔPO2 maps and parameterised with an exponential model of O2 wash-in and wash-out1. RESULTS: Figure 1 shows an image volume overlaid with a map of O2 wash-in and ΔPO2 time series of all the subjects scanned. The same exponential model was applied to the group average ΔPO2. CONCLUSIONS: These results are the first to show the feasibility of volumetric whole lung dynamic OEMRI. REFERENCES: 1 Kershaw et al. MRM 64:1838-1842;2010. 2 Deichmann et al. Neuroimage 12:112-127;2000. Thanks to University of Manchester, MRIF. ![Figure][1] [1]: pending:yes